Spray coating exhaust system



Jan. 29, 1935. A. R. CLARK 1,989,270

SPRAY COATING EXHAUST SYSTEM Filed Dec. 26, 1931 Q 2 Sheets-Sheet 2 I I r 3 m m m m [I] 1:] \I] [:1

spray dust a the air supply conduit shown in Fig. 3;

Patented Jan. 29, 1935 UNITED STATES $PRAY COATING EXHAUST SYSTEM Albert R. Clark, Toledo, Ohio, assignor to The De Vilbiss Company, Toledo, Ohio, a corporation of Ohio Application December 26, 1931, Serial No. 583,386

8 Claims.

This invention relates to an exhaust system particularly adapted for use in spray coating large portable objects, such as railway cars or motor transport trucks, to protect the operator from and fumes arising fromthe spraying operation.

In such systems, wherever a thin pneumatic curtain of flowing air is created between the operator and the object being coated the efliciency of the system depends not only upon the uniformity and continuity of the curtain butalso upon various other factors afiecting the velocity and volume of air supplied to the curtain or received therefrom.

The general object of the present invention is to provide improved means for securing the greatest emciency in the operation of an exhaust system of the type described, and more specifically to provide suitable adjustable means for regulating the input air so as to insure its proper distribution throughout the width of the curtain and at either side of the object being coated.

The invention will be more specifically described in connection with theaccompanying drawings, in which- Figure 1 is-a vertical transverse section of the invention;

Figure 2 is a side elevation thereof;

Figure 3 is a view similar to Fig. 2, but showing a modifled construction;

Figure 4 is an enlarged longitudinal section of Figure 5 isan enlarged transverse section of one of the input channels shown in Fig.4;

Figure 6 is a section taken on the line 6-6 of Fig. 5; and

Figure 'I is an enlarged view of the damper arrangement shown in Fig. 1H

As illustrated in the drawings; the exhaust system is adapted for use in spray coating a vehicle 10 and is installed within a shed 11 having a floor 12 on which the vehicle is supported.

As shown in Figs. 1, 2 and 6, the system comprises two input channels 13 -spaced far enough apart for the vehicle to bedisposed between them and having slots 14 opening upwardly for emitting continuous upwardly flowing curtains of air as indicated by the arows 15 in Fig. 1. The flow of air from these pneumatic curtains is received by a canopy 16 which is suspended from the roof of the shed 11 above the vehicle and which is provided with a sufllcient number of exhaust conduits or fiues '17 to prevent the flowing air and any fumes or spray dust picked up thereby from escap-v ing into the atmosphere within the shed.

The canopy is preferably provided with a skirt 20 arranged in accordance with the shape and size of the object to be coated, in such a manner that the air current will be directed toward the outlet flues' 17 with the least possible interruption to the flow by eddy currents or other obstructions. There is also a partition 21 within the canopy and having adjustable doors or dampers 22 and 23 which may be disposed as indicated in full lines in Fig. 1 to cause the air to flow directly upwardly from the curtain or asindicated in dotted lines to cause the air to flow over the top of the object and through the center of the partition when said top is being coated. v

Air is supplied to the input channels 13 by one or more fans 18 which draw the air from some point inside the building and the flow of the exhaust through the outlet flues 1'7 is induced by fans 19. As shown in Figs. 1 and 2, a conduit 24 leads fromthe fan 18 to a conduit 25 extending transversely beneaththe vehicle 10 and connecting the centers of the input channels 13 which taper toward their ends. In order to equalize the pressure in the two channels 13 a damper 26 is located in front of the entrance to the conduit 25 and may be adjusted to the proper angle by means of a. manually controlled element 27.

In the modification shown in Figs. 3 and 4 the fan 18 and the conduit sections 24 and 25 are located at one end of the object to be coated and are connected with input channels 28 which are tapered from one end to the other, each being provided with an input slot 29 through which the pneumaticpurtain is emitted. One or both of the channels 28 should be provided at the inlet end with a damper 30 which may be adjusted by the hand controlled element 31. J

In order to provide a substantial and rigid construction and to distribute the input air more equally throughout the length of the channel 28, it is desirable to construct the same as shown in Figs. 5 and 6. In this construction the slot 29 is formed between the side flanges of two channel bars 32 and the upper part of thechannel 28 is divided into a number of sections or chambers by cross bars 33, which are bolted to the bars 32 and rest upon shoulders formed in the concrete at the sides of the channel 28. Each of-these sections or chambers is partially separated from the main part of the channel 28 by a horizontal partition 34 and the effective area of this partition may be individually adjusted by a slidable damper 35 which may be manipulated by a suitable rod or tool inserted through the slot 29.

What is claimed is: 1. A spray coating exhaust system comprising channels with openings arranged to discharge a pneumatic curtain at each side of the object to be coated, a common air supply conduit leadingto said channels, means for supplying air under pressure to said conduit, and means adjustable to vary the relative division of the air between the different channels.

2. A spray coating exhaust system comprising channels with openings arranged to discharge a pneumatic curtain at each side of the object to be coated, a common air supply conduit leading to said channels, each channel decreasing in cross sectional area from its junction with the supply conduit to the end, means for supplying air under pressure to said conduit, and means adjustable to vary the relative division of the air between the difierent channels;

3. A spray coating exhaust system comprising a substantially horizontal channel with a slot in its upper face for discharging a pneumatic curtain at the side of the object to be coated, means for supplying air under pressure to said channel, and means for separately adjusting the air pressure in difierent sections along the length of the channel.

4. A spray coating exhaust system comprising a substantially horizontal channel with a slot in its upper face for discharging a pneumatic curtain at the side of the object to be coated, cross partitions dividing the upper portion of the channel into compartments, partitions partially separating said compartments from the lower portion of the channel, means for supplying air under pressure to the lower portion of the channel, and means for individually adjusting the efiective area of said last mentioned partitions.

5. A spray coating system comprising a sub- I stantially horizontal channel, means for supplying air under pressure to said channel, a chamber above said channel, a partition partially separating said chamber from the channel, the sides of said chamber being'offset from the sides of the channel to form shoulders, cross bars resting on said shoulders to form the ends of the chamber, and a pair of longitudinal bars secured to the cross bars, the sides of the respective longitudinal bars having depending flanges secured in spaced relation to each other to provide between them a narrow slot, from which a pneumatic curtain is emitted under pressure.

6. A spray coating exhaust system including a substantially horizontal channel with a slot in the upper face, partitions dividing the slotted portion of said channel into compartments, partitions partially separating said compartments from the main portion of said channel, means for supplying air under pressure to the main portion of the channel, and means to adjust the effective area of said last mentioned partitions.

7. A spray coating exhaust system comprising channels with slots arranged to discharge a pneumatic curtain at each side of the object to be coated, a common air supply conduit leading to said channels, means for supplying air under pressure to said conduit, means adjustable to vary the relative division of the air between the different channels, and means forming equalizing chambers between the main volume of each of said channels and the respective slots.

8. A spray coating exhaust system comprising channels with slots arranged to discharge a pneumatic curtain at each side of the object to be coated, a common air supply conduit leading to said channels, means for supplying air under pressure to said conduit, means adjustable to vary the relative division of the air between the different channels, and partitioning means disposed in each of said channels to distribute. the input air equally throughout the length of the respective channels.

. ALBERT R. CLARK. 

